Extensible drill collar



Sept. 26, 1961 J. s. BECK 3,001,596

EXTENSIBLE DRILL COLLAR Filed Feb. 20, 1958 5 Sheets-Sheet l 30g 65 32g3, g

a :1 I: C D 1 31b T a 50 :26 2 32a A. FIG/5A. 3/ g 3 32 FIG I4 30 30 65S. BECK 5 F1655 JUL/Us INVENTOR. F/6.5E.

BY mg m ATTORNEY Sept. 26, 1961 J. s. BECK 3,001,596

EXTENSIBLE DRILL COLLAR Filed Feb. 20, 1958 3 Sheets-Sheet 2IIIIIIIIIIIIIIIIIIIIIIII HIHIHII III! iliii F IG. 2.

JUL/US S. BECK INVENTOR.

FIG. 5. F l6. l4.

ATTQRNEY Sept. 26, 1961 J. s. BECK 3,001,596

EXTENSIBLE DRILL COLLAR 8 baa FIG. 9. N M

JULIUS s. BECK INVEN TOR.

A TTORNE Y United States PatentfO 3,001,596 EXTENSIBLE DRILL COLLARJulius S. Beck, Long Beach, Calif., assignor, by mesne assignments, toJ. Ed Hill, Inc., Houston, Tex., a corporation of Texas Filed Feb. 20,1958, Bar. No. 716,464 4 Claims. (Cl. 175-300) This invention relates toextensible devices for conneetion in drill strings when drilling oil andgas wells. Generally, such devices are for maintaining optimum weight ondrill bits and for jarring either up or down when required during rotarydrilling'operations. "Ihe optimum weight on the drill bit isaccomplished by adding a required number of drill collars to the stringbelow the present extensible device for continuing the verticaldirection of the bore hole. The jarring action referred to is applicableto both vertical and directional drilling.

' --Since the flexibility of a drill string increases with its increasein length, the deeper the bore hole the more diflicult it is to controlthe course of the bit downwardly in the earth. During drillingoperations, various impediments are encountered such as angularformations, boulders, crevices and pressures, all of which tend tochange the course of the bit from its intended direction. In order toaccurately control the bit it is desirable, from time to time, to applyand relieve longitudinal forces in the drill string at a point wellbelow the earths surface.

An object of the invention is to provide an improved extensible devicefor use in a drill string, and which device is capable of multipleoperations for meeting various requirements during a drilling operation.

A particular object of the invention is to reduce drilling time byreason of overcoming obstacles without withdrawing the drill string fromthe hole for attaching special tools.

Another object is to provide means'for substantially uninterrupteddrilling even though the drill string below the present device issubjected to cave-ins or other binding forces, such as the accumulationof drill solids in the bore hole.

A further object is to provide, in addition to the foregoing, anextensible and c'ontractible link in a drill string, which link willaccommodate the action of waves when used on a drilling barge. I

A particular object is to provide a device of the described classwithout threads and thereby prevent the device from coming apart in abore h'oleeven-though subjected to reverse rotation of the drillstringer the sudden release of accumulated torque therein.

Another particular object is to providean extensible bit control devicefor operation in a drill string below the earths surface and whichdevice is capable of being locked and unlocked relative to theextensible length thereof, yet one in which it is not necessary for theoperator 'to know the exact extended or contracted position of thedevice for its successful operation.

A further object is to provide, in a suspensionjlrfih ing device, a'reserve extension means for jarring or spudding even after the bit hasdrilled offfthatis, when the pipe has been extended for drilling amaximumdepth before the upper drill string is lowered for additionaldrilling, in which instance the entire weight of the string is on theweight indicator and the drill bit is ineffective.

ice

A still further object is to provide a slip joint in a drill string foraccommodating elongation due to the suspended weight of the drill stringabove the present device.

In the accompanying drawings of exemplary forms of the invention:

FIGURE 1 is an elevational view of the invention con nected in a drillstring. (All forms of the invention herein shown and described have thesame external appearance.)

FIGURE 2 is an enlarged broken vertical sectional view of the upperportion of FIGURE 1 showing a preferred seal at the upper end of themandrel and in sliding contact with the cylindrical inner surface of theupper body. FIGURE 2 also represents the inverted position of the lowerportion of FIGURE 1 and the seal arrangement on the opposite end of themandrel.

FIGURE 3 is a vertical sectional View of the upper cylindrical body on areduced scale as compared FIGURE 2. It is to be understood that thelower cylindrical body is substantially identical with the upper body,except it is inverted with respect thereto, and that one has internaldrill pipe connecting threads while the other has external drill pipeconnecting threads. and pin arrangement in FIGURE 1.) I

FIGURE 4 is a broken elevation of the upper portion of the mandrel andshowing the seal, the seal expanding spring and spring holder in theirassembled positions. Like FIGURES 2 and 3, FIGURE 4 also represents thelower portion of the invention in an inverted positio'm FIGURE 5 is anelevational view of a mandrel for sliding and locking action in theupper and lower cylindrical bodies.

FIGURE 6 is an enlarged perspective view of one of the seals asillustrated in FIGURES 2 and 5.

FIGURE 7 is a broken elevation and sectional view showing the installedposition of one of the two collar constructions for assembling theinvention.

FIGURE 8 is a broken perspective, shown in vertic section, of the upperend of the lower mandrel and particularly showing an arrangement of lugsin the upper end thereof for receiving the collar assembly.

FIGURE 9 is a perspective view of the impact collar forming a part ofthe collar assembl FIGURE 10 is a perspective view of a locking sleeve,mounted on the impact collar.

FIGURE 11 is an enlarged transverse section taken on line 11-11 ofFIGURE 4.

FIGURE 12 is an enlarged transverse section taken on line 12-42 ofFIGURE 5.

FIGURE 13 is a transverse section taken on line 13- 13 of FIGURE 8.

FIGURE 14 is an elevational view of a mandrel similar to FIGURE 5 butshowing a modified form of the invention having a different arrangementof mandrel lugs thereon. I

FIGURE 15 is a broken elevational view of a mandrel and showing afurther modified form of the invention by reason of the arrangement ofmandrel lugs thereon.

FIGURES 5A through 5F are schematic views illustrating some of thevraious positions of mandrel lugs relative to body lugs as in connectionwith the preferred form of the invention. (See FIGURE 5).

FIGURE 14A is a schematic view of a typical arrangement of mandrel lugsand body lugs in the first referred to modified form of the invention.(See FIGURE 14).. v

FIGURE 15A is a schematic view of atypical arrange;

I (Note the box.

ment of mandrel lugs and body lugs in the last referred to modified formof the invention. (See FIGURE 15.)

As shown in FIGURE 1, upper and lower cylindrical bodies and 21 areconnected with adjacent lengths of drill pipe 22 and 23 in a drillstring. Although the complete drill string is not shown, it is to beunderstood that the present device is located between the upper andlower ends thereof and that drill collars, not shown, are connected inthe drill string at desired locations. Preferably, the'outside diametersof the cylindrical bodies 20 and 21 are large enough that the presentdevice may be considered a special drill collar. As will become apparentas the description proceeds, the bodies 20 and 21 are identical in theirconstruction except one (20) is provided with internal pipe connectingthreads 24, whereas the other (21) has external pipe connecting threads25 in accordance with the usual practice of joining drill pipe. Theupper and lower bodies 20 and 21 slidably receive opposite ends of atubular'mandrel 26 having limited relative rotation therein andhereinafter described in detail.

Referring now to FIGURE 3, the upper body 20 includes the referred topipe threads 24 in its upper end, an axial passage 27 therebeneath largeenough to accommodate instruments lowered on wire lines, and a hydraulicchamber 28 of enlarged diameter beneath the axial passage. Immediatelybelow the hydraulic chamber 28, the axial diameter is further increased,as at 29-, to provide a shoulder 65 and vertical rows of spaced bodylugs 30 are provided on opposite sides of the body portion 29 forcoaction with mandrel lugs 31 on the outer surface of the mandrel 26near the ends of thelatter. The oppositely arranged vertical rows ofbodylugs 311 are shown in FIGURES 8 and 13 in connection with detailedillustrations of the lower cylindrical body 21. The mandrel lugs 31 arealigned in vertical groups on opposite sides of the mandrel 26 and arespaced for engagement between the body lugs 30. As viewed in FIGURE 5,the mandrel lugs 31 are round at their left ends and are joined by avertical rib 32 extending along the right side of each group of mandrellugs. It is to be noted that the distance between the outermost lugs 31of each group of mandrel lugs is less than the distance between theoutermost lugs of each group of body lugs 30. Referring now to FIGURES2, 4 and 6 a cylindrical seal 33 is provided at each end of the mandrel26. The seals 33 herein shown and described, together with theirassemblies for constantly urging the seals against the wall of thehydraulic chamber 28, are shown and describedin rny prior patents, Nos.2,819,878 and 2,819,879, both issued January 14, 1958. Each cylindricalseal'33 is'in sliding contact with a cylindrical hydraulic chamber 28and is tapered at its inner end for engagement witha correspondinglytapered surface 34 in each end of the mandrel 26. The seals 33 aresecured in place by means of circular shoulders 35 around the taperedportions of the seals, and which shoulders are engaged in circulargrooves 36in the mandrel tapers 34. The outer ends of the seals areinwardly tapered, as at 37, where they receive correspondingly shapedrings 38 of semi-resilient material, such as rubber impregnatedlaminated fabric. Outwardly of the rings 38 there are shoulderedspringholders 39,' the end surfaces 40 of which are shaped to engage the rings38 and the opposite shoulder surfaces are shaped to'receive the ends ofcoiled compression springs 41. There is a relatively thin integraltubular extension. 42 on the inner end of each spring'holder 39 andwhich extension engages the inner diameter of each ring 38 and seal 33;The purpose of the extensions 42 is to prevent the seals from becomingconstricted when subjected to high pressures, as for example, in deepwells where the circulating fluid pressures are relatively high; The

"ends of the springs 41 opposite the spring holder 39 are engaged .byshouldered removable spring holders/l3 shaped to fit the ends ofthe'hydraulic chambers 28. The

, contracted positions.

I! i 4 axial passage diameters 44 and 45 of the spring holders 39 and 43are preferably as large as the axial body passages 27. Set screws 46 inthe sides of the holders 39 and 43 maintain the springs 41 in theirassembled positions as shown in FIGURE 4.

All ofthe illustrated forms of the invention are held in coactiverelation by collar assemblies, generally designated by the numeral 47and shown in detail in FIGURES 7, 9 and 10. FIGURE 7 shows the collarassembly 47 in section, and FIGURE 8 shows an arrangement of inner andouter body lugs 48 and 49 as in opposing ends of both bodies 20 and 21.The collar assembly 47 is comprised of two primary components, an impactcollar 50 and a locking sleeve 51, the'adjoining ends of which haveinterfitting tapers 52 and 53. Since the assembled locations of thecollars 50 and sleeves 51 on the mandrel 26 are inwardly of the mandrellugs 31, the collars and sleeves are longitudinally split along oppositesides, as at 54 and- 55, to facilitate assembly. Preferably, theadjoining edges 54 and 55 of the collars 50 and 51 are pro.- vided withcoacting notches and projections 56 and 57, for holding the respectivehalves thereof against longitudinal displacement when inserting thecollars and sleeves in the ends of the bodies 20 and 21. An annularshoulder 58 in each body 20 and 21 engages the lugs 31 at the inner end59 of the collar 50; similarly, a shoulder 60 around the collar 50 atthe base of the taper 52 en: gages the inner end 61 of the sleeve 51.

The inner and outer lugs 48 and 49 in the ends of the bodies 20 and 21respectively engage lugs 62 and 63 on the collar 50 and sleeve 51. Asshown in FIGURES the pairs of body lugs 48 and 49 are oppositelyarranged with relation to. each other. A flange 64 around the outer endof the 'sleeve Sl engages the outer edges of the outer body lugs 49, butwhich flange is received within the body 20 or 21 and is flush with theend thereof.

When installing the collar assembly 47, the halves of the impact collarSG-are placed around the mandrel. and inserted in the body 20 or 21. Thecollar 50 and lugs 62 thereon are first rotated to pass between theouter body lugs 49 and then further rotated to pass between theinnerbody lugs 48. Further rotation causes the impact collar lugs 62 tobe positioned inwardly of the inner body lugs 48. Similarly, the twohalves of the locking sleeve 51 are placed on the mandrel and arerotated sons to cause the lugs 63 thereon to. fit beneath the outer'bodylugs 49. Set screws, not shown, may be 'employed through the body 20 or21 to secure the impact collars 50 and sleeves 51 against rotation;however, it has been found that frictional engagement is ordinarilysuflicient for this purpose. 7

Operation of the first described form of the invention hasto do withvarious functions such as suspension drilling, jarring, spudding anddetermining -whether or not a free point is above or below the presentdevice. A typical position for suspension drilling is'shown in FIGURE 5Aand has to dowith conventional clockwise rotation of the drill string asviewed from the earths surface. Here. the clockwise rotation of theupper drill string 22 imparts the same rotation'to the upper body 20;causing the body lugs 30 therein 'to engage the vertical rib 32 on themandrel 26 which, in turn, causes the lower mandrellugs 31 to interfitand engage body'lugs 31) in the lower man drel 21. -.A similar operatingposition is shown in FIG- URE 5F, but wherein the outer end mandrel lugscontact shoulders 65 in the bodies 20 and '21 outwardlyfvo'f the bodylugs 30; thus, FIGURE 5F illustrates an operation where the bodies 20and 21 are in their relative FIGURES 5C and SB represent engagementofthe upper body lugs 30 when the upper drill string 22 has beencounter-rotated. These positions are used, for example, when. jarring orspudding since the imparted counter-rotation through the mandrel 26causes the lower vertical ribs 32 to make sliding contact with the lowerbody lugs 30. FIGURES 5D and 5E show contracted and extended positionsof the bodies 20 and 21 when the upper and lower mandrel lugs 31 arepositioned for sliding action between upper and lower body lugs 30. Thisposition is obtainable when there is no rotary action or torque impartedin the upper drill string 22 and which position is for spudding or forfinding the free point (above or below the present device) when thedrill string is stuck in the hole. The term free point designates alocation of the drill string above or below the stuck portion, that is,a point or portion where the drill string is free in the bore hole.

The various described positions, FIGURES 5A through 5F are obtained byempirical tests by rotating, counterrotating and raising and loweringthe drill string. For example, the operator will know when the bit hasdrilled off in suspension drilling by increased weight on the weightindicator. The operator may readily position the device as shown inFIGURE 5A by first counter-rotating the upper drill string 22 to obtaina position as in FIG- URE 5C, raising the drill string slightly so as toposition the lower mandrel lugs intermediate the ends of the lower bodylugs 30, and then rotating the upper drill string clockwise to cause theengagement as shown in FIGURE 5A. This position is preferred forsuspension drilling since reserve jarring action may be obtained afterthe bit has drilled off. In the latter case, the operator counterrotatesthe upper drill string 22 and obtains the position illustrated in FIGURE5C; thus, the operator is in a position to spud or jar. Delayed actionjarring is obtained, either up or down, by stretching or applying weightto the upper drill string before disengaging any of the mandrel lugs 31from the body lugs 30.

The form of mandrel illustrated in FIGURE 14 has its upper mandrel lugs31a directed to the right relative to its vertical rib 32a, whereas itslower mandrel lugs 31a are directed to the left relative to theirvertical rib 32a. An operation of this form of the invention isillustrated in FIGURE 14A wherein both upper and lower mandrel lugs 31aare engaged with corresponding body lugs 30a during normal clockwiserotation. Among its several operations this arrangement provides up anddown jarring as above referred to and is desirable during certainoperations, such as reaming, and washover operations.

The mandrel 26b illustrated in FIGURE is primarily intended foroperations wherein full telescoping action is required; however, in viewof the foregoing explanation, it will be apparent that this form of theinvention is also adaptable for use in jarring and spudding operationsby applying clockwise and counterclockwise rotation to the upper drillstring and raising and lowering the same in the manner previouslydescribed. In FIGURE 15A the mandrel lugs 31b are disengaged from thebody lugs 30b, and the vertical ribs 325 are in sliding contact with thelatter.

In all forms of the invention, the contracted position of the presentdevice is limited by contact of the outermost mandrel lugs 31, 31a or31b with the shoulders 65 in the bodies and 21. Similarly, the extendedposition of the device is limited by contact with the innermost mandrellugs 31, 31a and 31b in contact with the impact collars 50.

The invention is not limited to the exemplary construction hereindescribed but may be made in various ways within the scope of theappended claims.

What is claimed is:

l. The combination of a drill string including spaced upper and lowersections, and a drill collar interposed between and connecting saidupper and lower string sections together for limited rotary and slidingmovement of one section relative to the other, said drill collarcomprising a tubular upper body secured at its upper end to the lowerend of the upper string section, a tubular lower body secured at itslower end to the upper end of the lower string section, said upper andlower bodies being coaxial and having spaced adjacent ends, a tubularmandrel having upper' and lower end portions telescoped for limitedrotational and sliding movement in the lower end portion of the upperbody and in the upper end portion of the lower body respectively, setsof vertically spaced body lugs provided on the inner surface of thelower and upper end portions of the respective upper and lower bodies,sets of vertically spaced mandrel lugs provided on the outer surface ofthe upper and lower end portions of said mandrel, said mandrel lugsbeing selectively received in the spaces between the respective bodylugs and said body lugs being selectively received in the spaces betweenthe respective mandrel lugs upon rotation and sliding of said bodiesrelative to the mandrel whereby to vary the overall length of the drillcollar, vertical ribs provided on the outer surface of the upper andlower end portions of the mandrel continguously with and at one side ofthe mandrel lugs in the respective sets, said body lugs when disposed inthe spaces between said mandrel lugs abutting said ribs to preventrotation of said bodies relative to said mandrel in one direction butpermit rotation thereof in the relatively opposite direction forwithdrawal of the lugs from their respective spaces, upper and lowersplit locking collars positioned on said mandrel in the respective upperand lower bodies and below and above the respective sets of mandrellugs, coacting means provided on said collars and in said bodies forretaining the former at fixed locations in the latter, the lowermost anduppermost mandrel lugs in the respective sets being engageable with therespective upper and lower collars whereby to limit the extent to whichsaid bodies may be slid away from each other on said mandrel; andinwardly projecting shoulders provided in said bodies above and belowthe respective sets of mandrel lugs, the uppermost and lowermost mandrellugs in the respective sets being engageable with said shoulders wherebyto limit the extent to which said bodies may be slid toward each otheron the mandrel.

2. The device as defined in claim 1 together with a pair of tubularseals of resiliently compressible material provided at the upper andlower ends of said mandrel and engaging the inner surfaces of therespective bodies, and springs positioned in said bodies and abuttingsaid seals for urging the latter laterally outwardly against the innersurfaces of the bodies.

3. In a drill string collar, the combination of a tubular body having afirst end adapted for connection to a drill string section and an opensecond end, a tubular mandrel having one end portion thereof rotatablyand slidably positioned in said body and projecting outwardly therefromat said second end of the latter for connection to another drill stringsection, a set of longitudinally spaced body lugs provided intermediatethe ends of said body on its inside surface, a longitudinal rib providedon the inside surface of the body at one side of and contiguously withsaid set of body lugs, a set of longitudinally spaced mandrel lugsprovided on said one end portion of said mandrel, said mandrel lugsbeing selectively disposed in the spaces between said body lugs inengagement with said rib whereby to lock said mandrel against sliding insaid body and prevent rotation of the mandrel in the body in onedirection but whereby to permit rotation of the mandrel in therelatively opposite direction for withdrawal of the mandrel lugs fromsaid spaces between the body lugs and facilitate sliding of the mandrelin the body, a split locking collar positioned in said body at a pointbetween the body lugs and said second end of the body, means in the bodyand on said locking collar for retaining the collar at a fixed point inthe body, said locking collar slidably receiving said mandrel and theadjacent mandrel lug in the set being engageable with the locking collarto limit the extent of outward sliding of the mandrel in said body, andan inwardly projecting shoulder provided in said body at a point betweensaid first end of the body and said body lugs, a mandrel lug in the setadjacent said shoulder being engageable with :thevlatter to limit theextent of inward sliding of the mandrel in said body.

4. The device as defined in claim 3 whereinsaid niens for retaining saidlocking collar in said body comprise 1 a set of circumferentially andlongitudinally offset keeper lugs provided inside the body, and a set ofcircumferentially and longitudinally offset keeper lugs provided on-said locking collar, said sets of keeper lugs being sep- :arablyinter-engageable upon rotation and sliding of the 1.0

2,029579 McCullough Feb; 4, 1936 2,066,794 Miller Jan. 5, 1937 2,819,879

Beck Jan. 14, 1958

